Work vehicles, such as various construction, forestry and agricultural machines, often operate off-road on uneven terrain. This rough terrain may require the work vehicles to operate in one or more off-level (or off-axis) conditions. These off-level conditions include forward and rearward pitch orientations as well as side-to-side roll orientations. The fuel tank and fuel sender thus must be configured appropriately to maintain fuel delivery to the engine in such off-level conditions. Typically this is accomplished by terminating the fuel sender or pump in a fuel sump. Fuel sumps are often “bowls” or the like mounted below the main fuel tanks. The idea is that the bowl-shape of the fuel sumps will help contain and maintain a volume of fuel surrounding the fuel sender to keep the machine running when off-level. However, some sumps have limited volumes that are insufficient to maintain engine operation in more severe off-level conditions or for a sufficient runtime. Also, in some machines where it is vital to maintain a minimum ground clearance, fuel sumps extending beneath the fuel tank may be impermissible or subject to damage from impact with ground objects.
To avoid these issues, fuel tanks have been devised with “inverted” fuel sumps, in other words, fuel sumps that extend into the interior volume of the main fuel tanks, rather than below them. However, because of vehicle space constraints and the need to maintain a minimum ground clearance in some machines, the main fuel tank may have a low profile, and consequently the upright walls of conventional inverted fuel sumps may be too short to contain a sufficient volume of fuel for operation in certain off-level conditions or for a sufficient overall runtime. Various other factors (e.g., other interior space limitations) may further prevent a sump from providing sufficient fuel volumes for operation in certain off-level conditions.